Optimally designed dielectric resonator oscillator (DRO) and method therefor

Abstract

A design methodology for a DRO that facilitates the development of the DRO. The methodology involves providing an electrical length of approximately 180 degrees or a multiple thereof from a region interior to a field effect transistor to a puck-resonator line interaction region, providing an electrical length of approximately 180 degrees or a multiple thereof from a region interior to the field effect transistor to the signal end of a source feedback transmission line, and providing an electrical length of approximately 90 degrees or an odd multiple thereof from a varactor diode signal ground to a puck-tuning line interaction region. Other aspects relate to a DRO resonator transmission line and a DRO tuning transmission line having a portion formed on a higher dielectric substrate to concentrate the electromagnetic field, and a portion on a lower dielectric substrate to expand the electromagnetic field near the dielectric resonator puck.

What it is claimed:  
     
         1 . A dielectric resonator oscillator for generating a signal having an operating frequency, comprising: 
 a field effect transistor having a gate, a drain, and a source;    a dielectric resonator puck having a puck-resonator line interaction region;    a resonator transmission line having a first end coupled to said gate of said field effect transistor and a second end coupled to a grounded impedance element;    wherein a first electrical length at said operating frequency exists from a region interior to said field effect transistor to a first region on said resonator transmission line that is closest to said puck-resonator line interaction region;    wherein a second electrical length at said operating frequency exists along a first straight line extending from said first region on said resonator transmission line to said puck-resonator line interaction region; and    wherein a sum of said first and second electrical lengths is approximately 180 degrees or an integer multiple thereof.    
     
     
         2 . The dielectric resonator oscillator of  claim 1 , wherein said resonator transmission line is configured as a microstrip transmission line.  
     
     
         3 . The dielectric resonator oscillator of  claim 1 , wherein said grounded impedance element has a characteristic impedance substantially the same as a characteristic impedance of said resonator transmission line.  
     
     
         4 . The dielectric resonator oscillator of  claim 1 , further comprising: 
 an output impedance matching circuit coupled to said drain of said field effect transistor;    a drain bias circuit for routing a drain bias voltage to said drain of said field effect transistor while substantially isolating said signal from said drain bias circuit;    a source feedback transmission line coupled to said source of said field effect transistor, wherein a third electrical length at said operating frequency of approximately 180 degrees or an integer multiple thereof exists between said interior region of said field effect transistor and a signal end of said source feedback transmission line; and    a source bias circuit for routing a source bias voltage to said source of said field effect transistor while substantially isolating said signal from said source bias circuit.    
     
     
         5 . The dielectric resonator oscillator of  claim 1 , further comprising: 
 a varactor diode having an anode and a cathode;    a bypass device for substantially coupling a signal ground to said cathode of said varactor diode;    a tuning transmission line having an end coupled to said anode of said varactor diode;    wherein a third electrical length at said operating frequency exists from said signal ground to a second region on said tuning transmission line that is closest to a puck-tuning line interaction region of said dielectric resonator puck;    wherein a fourth electrical length at said operating frequency exists along a second straight line extending from said second region on said tuning transmission line to said puck-tuning line interaction region; and    wherein a sum of said third and fourth electrical lengths is approximately 90 degrees or an odd integer multiple thereof at substantially a center of a range of said sum resulting from said varactor diode being operated across a tuning voltage range.    
     
     
         6 . The dielectric resonator oscillator of  claim 5 , wherein a fifth electrical length at said operating frequency exists along said tuning transmission line from an open end of said tuning transmission line to said second region such that the fifth electrical length causes said sum of said third and fourth electrical lengths to be approximately 90 degrees or an odd integer multiple thereof at substantially said center of sum range resulting from said varactor diode being operated across said tuning voltage range.  
     
     
         11 . The method of  claim 10 , wherein said port of said field effect transistor is a gate.  
     
     
         12 . The method of claim  9 , wherein said transistor is a bipolar transistor.  
     
     
         13 . The method of  claim 12 , wherein said port of said bipolar transistor is a base.  
     
     
         14 . A dielectric resonator oscillator for generating a signal having an operating frequency, comprising: 
 a field effect transistor having a gate, a drain, and a source;    a dielectric resonator puck having a puck-tuning line interaction region;    a resonator transmission line having a first end coupled to said gate of said field effect transistor and a second end coupled to a grounded impedance element;    a varactor diode having first and second terminals;    a bypass device for substantially coupling a signal ground to said first terminal of said varactor diode;    a tuning transmission line having an open end and an end coupled to said second terminal of said varactor diode;    wherein a first electrical length at said operating frequency exists along said tuning transmission line from said signal ground to a first region on said tuning transmission line that is closest to said puck-tuning line interaction region of said dielectric resonator puck;    wherein a second electrical length at said operating frequency exists along a first straight line extending from said first region on said tuning transmission line to said puck-tuning line interaction region; and    wherein a sum of said first and second electrical lengths is approximately 90 degrees or an odd integer multiple thereof at substantially a center of a range of said sum resulting from said varactor diode being operated across a tuning voltage range.    
     
     
         15 . The dielectric resonator oscillator of  claim 14 , wherein said tuning transmission line is configured as a microstrip transmission line.  
     
     
         16 . The dielectric resonator oscillator of  claim 14 , wherein said grounded impedance element has a characteristic impedance substantially the same as a characteristic impedance of said resonator transmission line.  
     
     
         17 . The dielectric resonator oscillator of  claim 14 , further comprising: 
 an output impedance matching circuit coupled to said drain of said field effect transistor;    a drain bias circuit for routing a drain bias voltage to said drain of said field effect transistor while substantially isolating said signal from said drain bias circuit;    a source feedback transmission line coupled to said source of said field effect transistor, wherein a third electrical length at said operating frequency of approximately 180 degrees or an integer multiple thereof exists between said interior region of said field effect transistor and a signal end of said source feedback transmission line; and    a source bias circuit for routing a source bias voltage to said source of said field effect transistor while substantially isolating said signal from said source bias circuit.    
     
     
         18 . The dielectric resonator oscillator of claim  14 : 
 wherein a third electrical length at said operating frequency exists along said resonator transmission line from a region interior to said field effect transistor to a second region on said resonator transmission line that is closest to a puck-resonator line interaction region of said dielectric resonator puck;    wherein a fourth electrical length at said operating frequency exists along a second straight line extending from said second region on said resonator transmission line to said puck-resonator line interaction region; and    wherein said third and fourth electrical lengths added together is approximately 180 degrees or an integer multiple thereof.  119 . The dielectric resonator oscillator of  claim 14 , wherein a third electrical length at said operating frequency exists along said tuning transmission line from an open end of said tuning transmission line to said first region such that said third electrical length causes said sum of said first and second electrical lengths to be approximately 90 degrees or an odd integer multiple thereof at substantially said center of sum range resulting from said varactor diode being operated across said tuning voltage range.    
     
     
         20 . The dielectric resonator oscillator of  claim 14 , further comprising: 
 a tune voltage bias circuit for routing a tune voltage to a cathode of said varactor diode while substantially isolating said signal from said tune bias circuit; and    a varactor grounding circuit for grounding an anode of said varactor diode while substantially isolating said signal from said varactor grounding circuit.    
     
     
         21 . The dielectric resonator oscillator of  claim 14 , wherein said resonator transmission line is configured as a microstrip transmission line.  
     
     
         22 . A method of designing a dielectric resonator oscillator that can generate a signal having an operating frequency, comprising: 
 providing a transistor having at least one port;    providing a dielectric resonator puck having a puck-tuning line interaction region;    providing a resonator transmission line having a first end coupled to said port of said transistor;    providing a varactor diode having first and second terminals;    providing a bypass device for substantially coupling a signal ground to said first terminal of said varactor diode;    providing a tuning transmission line having an open end and an end coupled to said varactor diode;    wherein a first electrical length at said operating frequency exists along said tuning transmission line from said signal ground to a first region on said tuning transmission line that is closest to said puck-tuning line interaction region of said dielectric resonator puck;    wherein a second electrical length at said operating frequency exists along a first straight line extending from said first region on said tuning transmission line to said puck-tuning line interaction region; and    wherein a sum of said first and second electrical lengths is approximately 90 degrees or an odd integer multiple thereof at substantially a center of a range of said sum resulting from said varactor diode being operated across a tuning voltage range.    
     
     
         23 . The method of  claim 22 , wherein said transistor comprises a field effect transistor.  
     
     
         24 . The method of  claim 23 , wherein said port of said field effect transistor is a gate.  
     
     
         25 . The method of  claim 22 , wherein said transistor is a bipolar transistor.  
     
     
         26 . The method of  claim 25 , wherein said port of said bipolar transistor is a base.  
     
     
         27 . The method of  claim 22 , wherein a third electrical length at said operating frequency exists along said tuning transmission line from said open end of said tuning transmission line to said first region such that said third electrical length causes said sum of said first and second electrical lengths to be approximately 90 degrees or an odd integer multiple thereof at substantially said center of sum range resulting from said varactor diode being operated across said tuning voltage range.  
     
     
         28 . A dielectric resonator oscillator for generating a signal having an operating frequency, comprising: 
 a field effect transistor having a gate, a drain, and a source;    a dielectric resonator puck having a puck-tuning line interaction region;    a resonator transmission line having a first end coupled to said gate of said field effect transistor and a second end coupled to a grounded impedance element; and    a source feedback transmission line coupled to said source of said field effect transistor, wherein an electrical length at said operating frequency of approximately 180 degrees or an integer multiple thereof exists between an interior region of said field effect transistor and a signal end of said source feedback transmission line.    
     
     
         29 . The dielectric resonator oscillator of  claim 28 , wherein said source feedback transmission line is configured as a microstrip transmission line.  
     
     
         30 . The dielectric resonator oscillator of  claim 28 , wherein said signal end of said source feedback transmission line is an open end.  
     
     
         31 . The dielectric resonator oscillator of  claim 28 , wherein said signal end of said source feedback transmission line is a signal grounded end.  
     
     
         32 . A method of designing a dielectric resonator oscillator that can generate a signal having an operating frequency, comprising: 
 providing a transistor having at least first and second ports;    providing a dielectric resonator puck having a puck-tuning line interaction region;    providing a resonator transmission line having a first end coupled to said first port of said transistor; and    providing a feedback transmission line coupled to said second port of said transistor, wherein an electrical length at said operating frequency of approximately 180 degrees or an integer multiple thereof exists between an interior region of said transistor and a signal end of said feedback transmission line.    
     
     
         33 . The method of  claim 32 , wherein said transistor comprises a field effect transistor.  
     
     
         34 . The method of  claim 33 , wherein said first port of said field effect transistor is a gate, and said second port of said field effect transistor is a source.  
     
     
         35 . The method of  claim 32 , wherein said transistor is a bipolar transistor.  
     
     
         36 . The method of  claim 35 , wherein said first port of said bipolar transistor is a base, and said second port of said bipolar transistor is an emitter.  
     
     
         37 . A dielectric resonator oscillator for generating a signal having an operating frequency, comprising: 
 a field effect transistor having a gate, a drain, and a source;    a dielectric resonator puck; and    a resonator transmission line having a first end coupled to said gate of said field effect transistor and a second end coupled to a grounded impedance element;    wherein a first portion of said resonator transmission line is formed on a first substrate having a first relative dielectric constant, and a second portion of said resonator transmission line is formed on a second substrate having a second relative dielectric constant less than said first relative dielectric constant, wherein said second dielectric is situated closer to said dielectric resonator puck than said first dielectric.    
     
     
         38 . The dielectric resonator oscillator of  claim 37 , wherein said first substrate comprises an alumina material.  
     
     
         39 . The dielectric resonator oscillator of  claim 37 , wherein said second substrate comprises a quartz material.  
     
     
         40 . The dielectric resonator oscillator of  claim 37 , wherein said first portion and/or said second portion of said resonator transmission line is configured as a microstrip transmission line.  
     
     
         41 . The dielectric resonator oscillator of  claim 37 , further comprising: 
 an output impedance matching circuit coupled to said drain of said field effect transistor;    a drain bias circuit for routing a drain bias voltage to said drain of said field effect transistor while substantially isolating said signal from said drain bias circuit;    a source feedback transmission line coupled to said source of said field effect transistor; and    a source bias circuit for routing a source bias voltage to said source of said field effect transistor while substantially isolating said signal from said source bias circuit.    
     
     
         42 . A method of designing a dielectric resonator oscillator that generates a signal having an operating frequency, comprising: 
 providing a transistor having at least one port;    providing a dielectric resonator puck;    providing a resonator transmission line having a first end coupled to said port of said transistor;    wherein a first portion of said resonator transmission line is formed on a first substrate having a first relative dielectric constant, and a second portion of said resonator transmission line is formed on a second substrate having a second relative dielectric constant less than said first relative dielectric constant, wherein said second dielectric is situated closer to said dielectric resonator puck than said first dielectric.    
     
     
         43 . The method of  claim 42 , wherein said first substrate comprises an alumina material.  
     
     
         44 . The method of  claim 42 , wherein said second substrate comprises a quartz material.  
     
     
         45 . The method of  claim 42 , wherein said first portion and/or said second portion of said resonator transmission line is configured as a microstrip transmission line.  
     
     
         46 . The method of  claim 42 , wherein said transistor comprises a field effect transistor.  
     
     
         47 . The method of  claim 46 , wherein said port of said field effect transistor is a gate.  
     
     
         48 . The method of  claim 42 , wherein said transistor is a bipolar transistor.  
     
     
         49 . The method of  claim 48 , wherein said port of said bipolar transistor is a base.  
     
     
         50 . A dielectric resonator oscillator for generating a signal having an operating frequency, comprising: 
 a field effect transistor having a gate, a drain, and a source;    a dielectric resonator puck;    a resonator transmission line having a first end coupled to said gate of said field effect transistor and a second end coupled to a grounded impedance element; and    a tuning transmission line having a first portion formed on a first substrate having a first dielectric constant, and a second portion formed on a second substrate having a second dielectric constant less than said first dielectric constant, wherein said second dielectric is situated closer to said dielectric resonator puck than said first dielectric.    
     
     
         51 . The dielectric resonator oscillator of  claim 50 , wherein said first substrate comprises an alumina material.  
     
     
         52 . The dielectric resonator oscillator of  claim 50 , wherein said second substrate comprises a quartz material.  
     
     
         53 . The dielectric resonator oscillator of  claim 50 , wherein said first portion and/or said second portion of said resonator transmission line is configured as a microstrip transmission line.  
     
     
         54 . The dielectric resonator oscillator of  claim 50 , further comprising: 
 an output impedance matching circuit coupled to said drain of said field effect transistor;    a drain bias circuit for routing a drain bias voltage to said drain of said field effect transistor while substantially isolating said signal from said drain bias circuit;    a source feedback transmission line coupled to said source of said field effect transistor; and    a source bias circuit for routing a source bias voltage to said source of said field effect transistor while substantially isolating said signal from said source bias circuit.    
     
     
         55 . A method of designing a dielectric resonator oscillator that generates a signal having an operating frequency, comprising: 
 providing a transistor having at least one port;    providing a dielectric resonator puck;    providing a resonator transmission line having a first end coupled to said port of said transistor; and    providing a tuning transmission line having a first portion formed on a first substrate having a first dielectric constant, and a second portion formed on a second substrate having a second dielectric constant less than said first dielectric constant, wherein said second dielectric is situated closer to said dielectric resonator puck than said first dielectric.    
     
     
         56 . The method of  claim 55 , wherein said first substrate comprises an alumina material.  
     
     
         57 . The method of  claim 55 , wherein said second substrate comprises a quartz material.  
     
     
         58 . The method of  claim 55 , wherein said first portion and/or said second portion of said resonator transmission line is configured as a microstrip transmission line.  
     
     
         59 . The method of  claim 55 , wherein said transistor comprises a field effect transistor.  
     
     
         60 . The method of  claim 59 , wherein said port of said field effect transistor is a gate.  
     
     
         61 . The method of  claim 55 , wherein said transistor is a bipolar transistor.  
     
     
         62 . The method of claim  61 , wherein said port of said bipolar transistor is a base.  
     
     
         63 . A receiver or transmitter having at least one dielectric resonator oscillator as defined in claims  1 ,  14 ,  28 ,  37  or  50 .